Transfer sheet and copy sheet systems and method of making



- Nov. 12, 1958 w. H. HOGE 3,410,711

TRANSFER SHEET AND COPY SHEET SYSTEMS AND METHOD OF MAKING Filed Nov.22, 1963 FIG.1

Transfer Coating Containing an Adhesive and Platelet Type Pigment.

-Paper Base Receptor Coating of Adhesive Having Glass TransitionTemperature Below About 40C.

aper Base Paper Base) FIG. 3

' ./-Transfer Coating Receptor Coating FIG. 4

Transfer wovswamele aawaapawqa a R e c e P 1 Coatingmmxretawzwewxmmmmmewmar Con g Planographic Plate Surface INVENTOR---Trans1er Coating BYVy lHlClm H. H099 Pager Base 5 Receptor 7" aCoating 7 C:

ATTORNEYS United States Patent 3,410,711 TRANSFER SHEET AND COPY SHEETSYSTEMS AND METHOD OF MAKING William H. Hoge, Rumford, Maine, assignorto Oxford Paper Company, New York, N.Y., a corporation of Maine FiledNov. 22, 1963, Ser. No. 325,624 Claims. (Cl. 117-36.1)

This invention relates to a system of coated papers for manifolding use.The invention includes transfer papers having a transferrable coating onone side thereof capable of being transferred to a receiving surface byapplication of a pressure such as by a ballpoint pen, stylus, pencil ortypewriter key, in the selective areas to which the pressure is applied.The invention includes manifold systems in which one or more sheets ofpaper having a pressure transferrable coating adhered to one sidethereof is used in combination with one or more sheets of paper having aspecially prepared image receiving surface or receptor coating adheredthereto. The invention also includes receptive papers which are veryeconomical in cost and which add to the quality of the transfer papersand the manifolding system.

Single or multiple copies of letters, invoices, shipping orders, accountstatements, and so forth are generally prepared today by using ordinarycarbon paper interleaved between the original and the copy papers andthe image transfer from the carbon paper transfer layer to the copypapers by applying writing pressure to the original paper.

Single and multiple copies have also been made without inserting theusual sheets of carbon paper between the copy sheets which are toreceive images made by application of pressure hand or machine. Suchsystems generally comprise an original sheet having a transfer coatingapplied to the underside thereof and one or more copy sheets havingimage receiving surfaces coated on the top side and a transfer coatingon the underside. Copies are made by applying pressure in a localizedarea to the top side of the original and the coating on the undersidethereof transferred in the localized areas to the receiving surfaces ofthe copy papers in contact with the transfer coatings on the originaland copy sheets.

1 Ordinary carbon paper is essentially composed of a paper base to whicha transfer coating is applied to one side thereof and is usuallycomposed of waxes, oils, suitable coloring pigments or dyes which aregenerally black but may be another color. The use of carbon paperinvolves the inconvenience of handling the separate sheets of paper.Conventional wax-oil transfer coatings are not commercially used on theback surfaces of the copy paper since the carbon transfer layer willsmear and soil the hands and clothing of people handling the original orcopies as well as transfer to other papers and surfaces that happen tocome into contact with the transfer coating during normal use.

Attempts to formulate and produce multiple copy systems withoutinserting the usual sheets of carbon paper between these copy sheets byapplying a transfer coating to the underside of the original and copysheets have not achieved, to date, any great degree of commercialsuccess. One of the few types of papers on the market today utilizes atype of system which involves a chemical reaction between an imbedded-or reoapsulated chemical in the transfer coat nad a second ingredientapplied to the topside of the copy paper. In this type of system, whenpressure is applied to the top of the original, it releases a chemicalcontained in the transfer coating and transfers it to the copy paper anda reaction takes place in the area of applied pressure to delineate thedesired image.

'Ihese chemical reaction types of reproduction papers are costly and thenumber of copies which can be repro duced by conventional mechanicalwriting pressure has been rather seriously limited. They all seem to bebased on dye systems which form light blue images which areunsatisfactory for optical scanning machines and which cannot be usedwith certain types of photocopy machines. The papers cannot becalendered after coating without prematurely releasing the chemicals andthis prevents their use in smooth, dense calendered papers which willgive the maximum number of copies. The chemical reaction papers alsohave problems in odor and fading.

Attempts to formulate and produce manifolding systems involving theapplication of a transfer coating to the reverse side of the originaland copy papers have not been significantly successful for one or acombination of reasons. Most attempts to produce a paper having atransfer coating on the reverse side thereof have resulted in coatingswhich are not sufficiently smudgeproof. Such a coating will transfereasily to the hands of the user or to other papers or surfaces it comesinto contact with under normal use and handling. Such transfer coatingsgenerally have an oily or waxy appearance in feel and are not dry.

Attempts to overcome and improve the smudging properties of such papershave resulted in poor image transfer to the copy paper or receivingsurface. In some cases, the transfer image is fragmented or quite hazyin (appearance, and, therefore, very difficult to read and hard on theeyes. This is especially true when more than two or three copies arebeing made. In other cases, the transfer coating is too difficult totransfer by means of ordinary writing pressureb y machine or handresulting in light images which are also difficult to read as well asseriously limiting the number of copies which can be made. Furtherdisadvantages of prior papers include instability to aging with moistureand/or heat resulting in a complete loss of the transfer properties ofthe transfer coatings or seriously diminished transfer properties.

The inability of prior reproduction papers having a transfer coating onone side thereof to go through normal and conventional printingprocesses without removal of portions of the transfer coating andgumming-up of the printing press has also been a serious problem. Otherdisadvantages of prior products include the necessity of high coatweight or special types of coatings which are costly, dusting of thetransfer coating as well as poor adherence of the coatings to the paperbase and generally poor paper characteristics. Inability of thereceiving surface to adequately hold the image has also been a problem.

This invention broadly involves a base sheet, preferably paper, having atransfer coating adhered to one side thereof which is capable of beingtransferred from the surface of the base sheet to a special receptivesurface by application of pressure to the reverse side of the paper andin which the transfer coating comprises a synthetic resinous adhesivehaving a glass transition temperature below about 40 C., and aninorganic pigment composed predominantly of platelets and in which theamount of adhesive is at least about 2% by weight based on the weight ofthe pigment.

The image receiving surface according to this invention comprises asynthetic resinous adhesive having a glass transition temperature belowabout 40 C. and which is essentially non-tacky to the casual fingertouch but which when compressed against the transfer coat by ordinaryhand or machine writing pressure develops sufiicient tack or adhesiveaflinity to remove transfer coat from the overlying surface.

In the drawing,

FIG. 1 shows a paper base having a transfer coating composed of anadhesive having a glass transition temperature below about 40 C. andplatelets-type pigments;

FIG. 2 shows a paper base having a receptor coating adhered thereto,having a glass transition temperature below about 40 FIG. 3 is a viewshowing the original paper having a transfer coating on the reverse sidethereof and a second paper base having a receptor, or image receivingsurface coating adhered thereto;

FIG. 4 shows a manifolding system in which the papers are stacked withthe transfer coatings on one side of the paper base in contact with thereceptor coatings also adhered on one side of a paper base. Theintermediate two papers have a stransfer coating on one side and areceptor coating on the other; and

FIG. 5 shows a paper base having a planographic printing surface adheredto one side thereof and a transfer coating adhered to the other. Thetransfer coating is in contact with a receptor coating on a second paperbase as shown in the drawing.

Various pigments can be used in the transfer coat according to thisinvention as long as they are predominantly of the platelet-type.Examples of pigments predominantly of the platelet-type include variousclays, such as China clay, kaolin clay and talc. Various other types ofpigments such as needle, cubicle and spherical types do not operatesatisfactorily according to this invention when used as the solepigment. Other types of pigments including the needle, cubicle andspherical as well as thermoplastic organic pigments, such aspolystyrene, can be substituted in part for the platelet-type pigments.The amount of such substitutions permissible, according to thisinvention, will, of course, vary not only with the type of plateletpigment used but with the type of needle, cubicle or spherical pigmentused. It is, therefore, not possible to set forth exact amounts of thevarious needle, cubicle or spherical type pigments which can besubstituted in part for the platlet-type pigments but this could readilybe determined by routine experimentation by those skilled in the artwith respect to any particular pigment system.

The amount of adhesive which can be used to bind the pigments to formthe transfer coating has been determined to be between about 2 and bweight based upon the weight of the pigments. Generally, the use ofabout 3% by weight of the adhesive when using clay as the sole pigmenthas been found to be advantageous. The use of an adhesive in excess ofabout 15% by weight seriously diminishes the transfer properties of thecoating while the use of adhesives below about 2% by weight does notresult in sufficient bonding power of the transfer coating to the base.The particular adhesive content referred to above was determined byusing a common base paper stock having no release coating thereon. Thus,the use of release coatings, which is possible but not necessaryaccording to this invention, may vary the minimum and maximum amounts ofadhesives as will be appreciated by those skilled in the art. The typeof pigment used will also offset the amount of adhesive and the 12 to15% adhesive level will be of importance only when there are largeamounts of hard-to-bind pigments, such as certain needle shapedmaterials, with the clay.

Various bases can be used for both the transfer and receptor coatingsincluding coated and uncoated base paper stock. Transfer coatings onplastic films give very sharp images. It is an advantage of thisinvention, however, that conventional base stock commonly used forcoatings can be used without previous treatment to hold both thetransfer and receptor coatings.

The pigments referred to above which can be used according to thisinvention in the transfer coating are not used to impart color to thetransfer coating and it is the combination of the particular type ofpigments with the particular type adhesive in particular ratios whichgives the transfer coating the characteristics of internal weakness andfracturing which control the ability to transfer. Ordinarily, thesetransfer coatings containing the platelettype pigment will be white. Itis, of course, possible to transfer a white image to a surface ofcontrasting color but it is advantageous to add a coloring material tothe transfer coating which does not interfere with the transferproperties or the other advantageous properties of the transfer coating.This will permit the use of a white or substantially white receptorsurface and the image transferred to the receptor surface will then beof contrasting color to the receptor surface and easily legible.

Various coloring materials can be incor orated into the coatingcompositions such as carbon black, red oxide, chromium oxide andphthalocyanine pigments. Examples of specific commercial type pigmentswhich have been used include carbon blacks marketed by Columbian Carbonunder the trade name Aquablak, red oxides marketed by the HarshawChemical Company under the trade name Aurasperse Red Oxide W304l,chromium oxides marketed by the Harshaw Chemical Company under the tradename Aurasperse Chromium Oxide Green W6017, phthalocyanine pigmentsmarketed by the American Cyanamid Company under the trade namesCalcotone Blue G and Calcotone Green G. Water-soluble dyes can also beused as coloring materials. An example of a water-soluble dye which canbe used is one marketed by the Allied Chemical Company under the tradename Soluble Blue P.

The amounts of coloring material which can be used Will vary quitewidely depending upon the particular coloring material being used andthe desired shade and depth of color in transfer coating.

In calculating the percent by weight of adhesive which can be usedaccording to this invention, the calculation has been made with respectto the platelet-type or predominantly platelet-type pigment which is notbasically used as a coloring material according to this invention. Sincevery little of the coloring material or pigment is required, this factorcan be ignored to some extent. If, however, large amounts of a coloredpigment are employed, this might very Well alter the percent of adhesiveused according to this invention, es ecially if the coloring material isone which is difiicult to bind by adhesives.

The coat weights of both the transfer and receptor coating can be quitelow according to this invention. The coat weight of the transfer coatingshould be sufficient so that a sharp deeply colored image can betransferred but not sufliciently high so that the transfer coating willlose its scuff resistance. Generally, a coat weight of between about 3and 6 pounds per ream can be used according to this invention but, ofcourse, it is advantageous to use a coat weight as low as possible froma cost standpoint. The coat weight of the receptor coating is preferablyabout 1-2 pounds per ream or below and only has to be of a sufficientcoat weight so that it will adequately receive and hold the transferredimage. Some compositions when applied at a coat weight of about 1 to 2pounds per ream will not be sufliciently receptive and in which casehigher coat weights should be applied which will possess the desiredtack or receptive properties.

Both the transfer coating and the receptor coating can be coated on asuitable base, preferably paper, by any conventional coating process. Nospecial coating procedures and no special mixing procedures of eitherthe transfer coating composition or the receptor coating composition arerequired.

The transfer coating of this invention can be calendered orsupercalendered by conventional calendering equipment without anysignificant loss of its advantageous properties and particularly withoutany significant loss of its transfer properties. The calendering of thetransfer coating adhered to the base reduces the caliper of the sheetand imparts to it improved manifolding characteristics, improvedsharpness of image without significant degradation of image darkness orshade and more copies can thus be obtained than with an uncalenderedmanifolding system. Calendaring also renders the transfer coating smoothand gives it a shiny appearance.

The calenderability of the transfer coating also permits a much moreeconomical process to be employed where the transfer coating is to beadhered to the back side of a duplicating master which normally would becalendered. In many instances, it is very desirable when imaging amaster such as a planographic printing plate to have one or more copiesimmediately available prior to sending the plate out to the printer forthe production of the copies. This can readily be accomplished by usinga planographic printing plate with a transfer coat on the back side, andplacing behind it a receptive coated sheet with the receiving surface incontact with the transfer coating. The printing plate is imaged in theusual manner. Thus, by imaging the printing plate, a copy issimultaneously made.

Most duplicating masters, such as planographic plates, requirecalendering to insure smoothness and proper functioning for productionof optimum quality copies. Con ventional transfer coatings, however,particularly those of the wax type, cannot be calendered since theysmear, come apart, foul up the calendering rolls or lose their transferproperties. Thus, with conventional type transfer coatings, it would benecessary to (1) place zrplanographic printing coating on to a suitablebase such as paper, (2) then calender the planographic printing surface,(3) and finally send through a coater to apply the transfer coatingopposite the planographic printing coating, dried and then rerolled.

Duplicating masters such as planographic printing plates having atransfer coating on the opposite side can be prepared, according to thisinvention more economically than using the above sequence. Theplanographic printing coating is applied to one side of the paper and atransfer coating is applied to the opposite side of the papersimultaneously or by means of a tandem coater which is capable ofsuccessively applying the two coatings Without an intermediate rollingup of the paper. As a second and final step, the sheet with bothcoatings can be run through conventional calendering equipment. Thecalendering thus not only accomplishes the required calendering of theplate surface but also adds the advantages noted above with respect tothe calendered transfer coating.

The particular type of planographic printing coating is not a part ofthis invention and any variously known planographic printing coatingdescribed in numerous patents and literature references can be used.Examples of planographic coatings which can be used includeinsolubilized polyvinyl alcohol and insolubilized carboxymethylcellulose.

The adhesives used to form the transfer coatings should contain asignificant quantity, such as 20% or more, of a resin with a glasstransition temperature below about 40 C. The term glass transitionrefers to the characteristic change in polymer properties from those ofa relatively hard, brittle, glassy material to those of a softer, moreflexible material or vice versa as the temperature is raised or loweredthrough the glass transition temperature. An adhesive or polymer havinga glass transition temperature below about 40 C. when coated on asuitable base such as paper will normally be readily deformable andprobably slightly tacky if adequate coat weights are used.

The transfer coat has such a high proportion of clay-like platelets tocause it to be very dry and non-tacky, regardless of the glasstransition temperature of the adhesive used. The purpose of the softadhesive is to maintain a deformability and a plasticizing qualitty inthe transfer coat. A transfer coating prepared from hard adhesives suchas starch or casein could be used for transfer to a suitable receptorcoating but it would have other disadvantages which would greatly reduceits value. The hard adhesives form transfer coatings which are brittle,they tend to fragment off when the substrate paper is folded or flexedand they are too dusty for general use. However, in some cases it may bedesirable to replace a portion of the flexible adhesive with smallquantities of hard adhesives in order to give the coating mixture theviscosity or levelling characteristics which are sometimes required foroptimum high speed coating machine operation. Care must be taken tomaintain a low enough level of total adhesive to allow the transfer coatto be removed from its base and at the same time retain a sufficientlyhigh level of flexible adhesive to obtain the desirable cleanliness andperformance properties.

It is well known in the art of calendering printing papers that thedusting characteristics of any coating based on pigment and brittleadhesive can be improved by the addition of small amounts of fattymaterials such as calcium stearate and the same principles apply to thetransfer coat of this invention. The fluidity or softness of theadhesive also tends to give a very sharp, nonfragmented and nonhazyimage.

The receptor coatings of this invention are formed of a soft resinousmaterial having a glass transition temperature below about 40 C. withthe pigmentation and coat weight controlled to produce a receptor coatwhich is essentially non-tacky to the finger touch but which has a tackyadhesive effect on the lightly bonded pigment particles in the transfercoat when the two coatings are pressed together. This very desirableblend of properties for the receptive coat can be obtained by the use ofa soft, tacky resin which normally would be tacky to the finger touchand which normally could not be wound into a roll of paper withoutcausing the successive plies to be blocked or glued together. The key tothe control of these problems is the careful control of the thickness ofthe coating of the soft resin. It was found that extremely thin coatingsof the soft tacky resins are not tacky to the finger touch, they do notcause blocking in the roll of paper, and they retain all of the afiinityfor the pigment in the transfer coating to give very good manifoldingperformance. The optimum coat weight for the receptor coat is in therange of 0.5 to 2 pounds per 3000 sq. ft., with a rough paper {equiringslightly more and a very smooth paper slightly ess.

The use of soft resins as receptor coatings in manifolding systems isold in the art but these prior papers were never of any commercialsignificance for several reasons. The soft resins could never be usedbecause of the previously mentioned problems of the receptive coatedpaper blocking together in the roll. The slightly harder resins whichdid not cause blocking were not sufficiently receptive to be ofcommercial interest. These slightly harder resins could be used to aslightly better advantage by increasing the thickness of the receptivecoating but this placed them at a severe economic disadvantage. In somecases the resinous receptor coatings were modified for greaterreceptivity and less tackness through the addition of certain types ofsoft waxes but this gave a surface with very poor receptivity toprinting inks and this prevented the commercial success of the product.The prior receptive coatings were always hindered by the fact that thetransfer coatings tended to be Waxy in composition and the resinousreceptor coats had poor afiinity for the wax. In contrast, the resinousreceptor coatings have very excellent afiinity for the lightly bondedclay-like pigment particles in the transfer coat formulated according tothis invention. The extremely thin receptor coat of the soft tackyresins to prevent the paper from blocking in the roll, offer an economicadvantage over the heavier coatings. The receptor coat of the inventionalso has very eX- cellent affinity for conventional printing inks usedin the business forms industry.

It may be advantageous, depending upon the particular adhesive used, toadd a small amount of pigment to the receptor coating adhesives in orderto impart whiteness or a color thereto. The pigments should be added insmall amounts because they tend to increase the minimum workablethickness of the receptive coat. If the thicker and more expensivepigmented coating is desired, it can be used to give good results withthe transfer coatings according to this invention. Excessive pigmentcauses a serious deterioration in the performance of the receptorcoatings and it has been found that if the weight of the pigment exceedsabout 60% of the total weight of the pigment-adhesive mixture, thereceptivity is seriously impaired and even at that level of pigment, thecoat weight of the receptor coat must be increased to obtainsatisfactory performance.

Thus, the particular type of polymer or resinous material which can beused as the adhesive or in formulating the adhesive for both thetransfer and receptor coating according to this invention is quitebroad, so long as it is an adhesive or has adhesive properties forbinding platelet-type pigments such as clays and talcs to themselves andto a suitable base such as paper and that the adhesives as a whole havea glass transition temperature below about 40 C. under normal humidityand temperature conditions under which the paper is to be used.

Examples of synthetic resinous materials which can be used according tothis invention for the receptor coating or in the transfer coatinginclude polybutadiene, poly-nbutylacrylate, poly-n-butylmethacrylate,poly-n-decylmethacrylate, polydimethylbutadiene, polyethyl acrylate,poly- Z-ethyhexyl acrylate, polyethylene glycol iso-butyratemethacrylate, poly-n-hexadecylacrylate, poly-n-hexylmethacrylate,polyisobutyl acrylate, polyiso-outylene, polyisoprone, polymethacrylate,poly-n-octylacrylate, poly-noctylmethacrylate, poly-n-propyl acrylate,poly-n-propyl methacrylate, poly-n-tetradecyl acrylate,poly-n-tetradecyl methacrylate, urethane rubber, polyvinyl acetate, andso forth. Various other adhesives can also be used as will be apparentto those skilled in the art.

There are also a number of other synthetic polymeric resinous adhesiveswhich possess a glass transition temperature above about 40 C. which canbe treated by the addition of plasticizing agents so that the adhesiveas a whole will possess a glass transition temperature below about 40 C.Polyacrylic acid is an example of such an adhesive. Although thisadhesive has a glass transition temperature above 40 C., films formedtherefrom are hygrosopic and under normal conditions of humidity andtemperature under which the transfer paper or receptor coating will beused, the film will take on water which will plasticize the filmrendering it flowable and soft and will possess a glass transitiontemperature under such conditions below about 40 C. Examples of otheradhesive materials having a glass transition temperature above 40 C.

which can be lowered by the addition of plasticizing agents includepolyacrylonitrile, cellulose acetate, cellulose nitrate, polyethyleneglycol dimethacrylate, polyethylene glycol terephthalate, polyisopropylmethacrylate, polytertiary butyl acrylate, polytertiary butylmethacrylate,

polymethyl methacrylate, polyvinyl alcohol, polyvinyl The transfercoating of this invention has the particular advantage of requiring nooily, waxy, fatty, greasy, migratory or evaporatable materials forsatisfactory performance. These additions, used in customary transfercoatings result in bleeding of dyes from transfer coatings or adjacentsurface coatings, penetration of coating materials into or through thepaper, or evaporation of materials from the coating which would alterthe properties of the transfer coating to cause poor aging properties.This is particularly important if the transfer coating is to be used tobe placed on the reverse of a paper planogra-phic printing plate, whichis easily damaged by migratory plasticizers and oils. Thus, althoughthere is described above the possibility of altering some adhesivematerials by, for example, the addition of plasticizers, the additiveagents should be carefully selected and the amounts thereof limited topreserve as much as possible the advantageous properties of the transferfilms of this invention. Plasticized adhesives can be used in either thetransfer coat or in the receptor coat of this invention so long as theplasticized resin systems retain the previously described propertiesrequired for functionability and the shelf like stability andnon-migrating characteristics required by the end use application.

It has also been found that the papers prepared according to thisinvention have a major advantage over previously produced papers of thistype in the fact that there is no apparent loss in copying quality ifthey are used at higher temperatures, such as 30 to 100 C. The transfercoating is essentially unchanged because its performance is dependentupon the network of inorganic pigment particles and this network isrelatively insensitive to heat. The receptive coating is a materialwhich is naturally tacky and soft at room temperature as well as highertemperatures and the careful control of coating thickness required forsatisfactory properties at room temperature also yields satisfactoryproperties at the higher temperatures.

Although adhesives having a glass transition temperature below about 40C. can be used according to this invention the most advantageousadhesives are those which possess a glass transition temperature belowabout C. If the adhesives have a glass transition temperature belowabout 20 C., the adhesive and the transfer coating will more definitelymaintain the flowability and softness required by the adhesive in thetransfer coating. Adhesives having a glass transition temperaturebetween 20 and 40 C, can in most instances be utilized according to thisinvention but the possibility always exists that such resins underparticular operating conditions may become too hard or brittle.

The adhesives or polymers thus used according to this invention are softadhesives which coalesce at approximately room temperature. They possesshigh extensibility and can be stretched. They are viscous and flowableat the temperature and humidity conditions under which they are used.

The following working examples illustrate various coating formulationswhich can be applied to a standard base stock paper to produce thereceptor coatings or receptor papers according to this invention:

Coating Compositions Parts by Parts by Weight (Wot) Weight (Dry) Example1:

HT clay 60% solids 50. 0 60/40 styrenebutadiene copolymer emulsion at48% solids. 50.0 24 Example 2:

HT clay 70% solids 50. 0 60140 st-yrene-hutadiene copolymer emulsion at48% solids. 91. O 43. 7 Water 06.0 Example 3:

HT clay 70% solids 32. 6 22. 8 Acrylic film forming emulsion at;

46% solids 62. 0 2S. 5 Water 40. 4 Example 4:

HT clay 60% solids 21.8 13. 1 Water disporsiblo titanium dioxide solids8. 8 4. 4 /40 styrenebutadiene at 48% solids 45. 5 21. 8 Water 33. 0Example 5:

HT clay 60% solids... 21 8 13.1 Water dispersible titai m d ide 50%solids 8. 8 4. 4 Acrylic fihn forming emulsion 46% solids 47. 4 21. 8Water 31. 0 Example 6:

HT clay 60% solids 21. 8 13. 1 Water dispersible titanium dioxide 50%solids 8. 8 4. 4 Acrylic film forming emulsion copolyrner 46% solids 47.4 21. 8 Example 7:

HT clay 60% solids 21. 8 13. 1

Coating Compositions Parts by Parts by Weight (Wet) Weight (Dry) Waterdispersible titanium dioxide 50% solids 8. 8 4. 4 Butyl rubber emulsionpolymer 56% solids 20. 6 11. 5 Polyterpene resin 50% solids 20. 6 10.3Example 8:

Butyl rubber emulsion polymer 56% solids 20. 6 11. 5 Polyterpene resin50% solids 20. 6 10.3 Flue gas calcium carbonate 21. 8-27. 2 Example 9:

Acrylic sel -cross-linking emulsion polymer 45% solids 20. 9. 0 Oxalicacid (dry). l. 0 1.0 Water 20.0 Example 10:

Acrylic seli-cross-linking emulsion polymer 45% solids 10.0 4.Polystyrene emulsion 45% solids 10.0 4. 5 Water 20.0 Example 11:

Acrylic self-cross-linking emulsion polymer 45% solids 10. 0 4. 5Polystyrene emulsion 45% solids. 10.0 4. 5 Cationic fatty acidcondensate 6% solids 1. 5 09 Water Example 12:

Acrylic selI-cross-linking emulsion polymer 45% solids 15.0 6. 75Cationic fatty acid con 60/40 styrene butadiene emulsion copolymer 48%solids 32.6 15.0 Water 68. 0 Example 15:

Acrylic emulsion copolymer, 46%

solids 32. 6 15. 0 Sodium alginete, 1% solids" 0.34

Example 16:

Polyvinyl acetate emulsion copolymer, 54% solids 27. 8 l5. 0 Butylbeuzyl phthalate 5. 0 5. 0

The reference to percent solids in all of the above examples refers tothe percentage of solids contained in an aqueous medium. The acrylicemulsion used in Examples 3 and 5 was acrylic emulsion marketed by Rohm& Haas under the trade name Rhoplex AC33. The acrylic emulsion used inExamples 6 and 15 was one marketed by Rohm & Haas Company under thetrade name Rhoplex B-S. The polyterpene resin used in Examples 7 and 8was marketed by the Pennsylvania Industrial Chemical Corporation underthe trade name Piccolyte 8-70. The self-cross-linking emulsion used inExamples'9, 10, 11 and 12 was marketed by Rohm & Haas under the tradename Rhoplex K-3. The cationic fatty acid condensate used in Examples 11and 12 was marketed by the American Cyanamid Company under the tradename Cyron.

The following working examples illustrate various coating formulas whichcan be applied to a standard base stock paper to produce the transfercoatings or transfer papers according to this invention:

Coating Compositions Parts by Parts by 7 Weight (Wet) Weight (Dry)Example 17:

HT clay 60% solids 50-58 -35 60/40 styrene-butadiene 48% solids. 2. 5-3.0 1. 20-1. 44 Carbon black solids 2. 0-3. 0 0. 70-1. 05 Water -60Example 18:

HT clay solids 72. 6 43. 6 Acrylic emulsion copolymer, 46%

solids 1. 8 0. 60/40 styrene-butadiene copolymer emulsion 48% solids 1.8 0.86 Sodium alginate 1% solids 3.0 0.03 Aurasperse Red Oxide W 304164% solids 20.0 12. 8 Water 1. 0 Example 19:

HT clay 60% solids 72.6 43. 6 Acrylic emulsion copolymer, 46% 1 8 0 85solids Coating Compositions Parts by Parts by Weight (Wet) Weight (Dry)60/40 styrene-butadiene copolymer emulsion, 48% solids .8 0.86Aurasperse Chromium Oxide Green W-6017 68% solids 18.6 12. 6 OalcotoneGreen G Paste 20% solids 3.2 0 64 Water 1.0 Example 20:

HT clay 60% solids 72.6 43. 6 Acrylic emulsion copolymer 46% S ids 1.80.85 60/40 styrene-butadiene emulsion copolymer l. 8 0. 86 CalcotoneBlue G Paste 20% sol s 12.0 2.4 Water. 1. 1 Example 21:

' HT clay at 60% solids 47. 7 28. 6 1 Soluble Blue P dye 0. 6 1. 7Acrylic emulsion copolymer, 46%

solids 0.6 0 27 60/40 styrene-butadicne copolymer emulsion, 48%solids 1. 7 0. 82 Water 49. 4 Example 22:

HT clay 60% solids 305.0 183.0 60/40 styrene-butadiene copolymeremulsion, 48%. solids 8. 8 4. 32 Carbon black, 35% solid 37.0 12.45Sodium algiuate, 2% soli 106. 5 2. 13 Water Example 23:

Lamp black, dry 3. 2 3. 2 HT clay, dry 47.6 47. 6 Polystyrene resin ofed molecular weight of 350, with melting point (ball and ring) of 50 C6. 0 6. O 0. 7 0.7 40.0 20. 0

The acrylic film forming emulsion copolymer used in Examples 18, 19, 20and 21, was marketed by Rohm & Haas Company under the trade name Rhoplex13-5. The carbon black in Examples 17 and 22 was manufactured byColumbian Carbon Company under the trade name Aquablak B. The AurasperseRed Oxide and Aurasperse Chromium Oxide were red and green pigmentsmarketed by the Harshaw Chemical Company. The Calcotone Green G and theCalcotone Blue G were phthalocyanine pigments marketed by the AmericanCyanamid Company under the above names. The water soluble=Blue P wasmarketed by the Allied Chemical Company under that trade name. Thepolystyrene resin in Example 23 was marketed by the PennsylvaniaIndustrial Chemical Corporation under the name of Piccolastic A-SO.

Transfer coatings or transfer papers were also made in a similar mannerto that set forth above employing an HT clay wafer dispersion as apigment and carbon black as the coloring matter and using as adhesives amixture of 60/40 styrene-butadiene copolymer emulsion and astyrene-maleic anhydride copolymer in which the styrenebutadienecopolymer was present at about 1.11% and the styrene maleic anhydridecopolymer was present at about 3.86% by weight based on the weight ofthe clay.

Polyvinyl methyl ether-maleic anhydride was also substituted for thestyrene maleic anhydride copolymer in the same weight percentage as thestyrene maleic anhydride copolymer.

Example 14 shows the production of two separate transfer coatings, onein which the styrene-butadiene was 2.5 percent, and carbon black 2.0percent and the other 3.0 percent styrene-butadiene and 3.0 percentcarbon black.

The transfer coating formulations set forth in the above examples wereall coated on one side of a conventional untreated paper web basebetween about 2 and 5 lbs. per ream and dried. The reverse side of thepaper base Web was coated with the receptor coating formulation ofExample 15 at a coat weight of between about 0.5 and 2 lbs. per ream anddried. The resulting web was cut into sheets which had a transfercoating on one side and a receptor coating on the other.

The transfer coatings were essentially dry and smudgeproof and had nooily or waxy appearance or feel, would not rub off onto other papers oronto hands during normal use or handling, and those papers having thetransfer coating and/or the receptor coating adhered thereto had goodpaper characteristics and good handling characteristics.

The receptor coatings were printed upon by conventional printingprocesses and the printing characteristics were excellent. The printingof the receptor surface of the papers with a transfer coating on theback also exhibited excellent printing characteristics withoutinterference of the function of the transfer coating and the transfercoating did not come off during the printing process, or in any mannerfoul up the printing press.

The sheets of paper having the transfer coating on one side and thereceptor coating on the other were assembled in the same manner as shownin FIG. 4 but using ten sheets in the same type combination instead ofthe four shown in the drawing. The first paper had a receptor coating ontop and the last paper had a transfer coating on the bottom.

Writing pressure by means of a typewriter was applied to the top paperand that portion of the transfer coating corresponding to the selectedarea of applied pressure by the typewriter keys readily transferred tothe receptor coatings reproducing the image pressed on the top paper asshown in FIG. 3. In all cases, a legible image was produced on the tenthsheet. The images produced especially on the first five copy sheets,were sharp, unfragmented, had a dense color and were easily and readilylegible. The image received on the receptor coating was not smearedthrough normal handling of the copy paper.

Similar tests on sets of five copy sheets showed that any of thetransfer coatings as set forth in Examples 17- 23 give good quality copywith any of the receptor coatings set forth in Examples 1-16. All testsresulted in substantially the same results as referred to above withrespect to the use of the transfer coatings when used in conjunctionwith the receptor coating set forth in Example 15.

Although the transfer coatings can be transferred by means of writingpressure to ordinary papers of the various kinds in use today, thecombination of the transfer papers of this invention with the receptorpapers of this invention is particularly advantageous. The specificityof transfer of the transfer coatings to the receptor coatings results inthe production of a much clearer, darker and sharp image than would beobtainable with ordinary papers. In addition, the transfer coatings aremuch easier to transfer by means of writing pressure to the receptorcoatings and thus many more legible copies can be produced by using thereceptor coating of this invention than would be possible with ordinarypapers. This specificity of transfer of the transfer coatings to thereceptor coatings does not, however, interfere with the smudge-proofnessof the transfer coating and the transfer coating will not be transferredaccidentally or scuff off onto other papers during ordinary handlingthereof nor will it transfer to or scuff off onto the receptor coatingthereon during normal use or handling. In spite of this smudge-proofnessof the transfer coating toward the receptor coating during ordinaryhandling, the transfer of the transfer coating to the receptor coatingby means of writing pressure was excellent. The transfer coatings, aswell as the receptor coatings of this invention, were clean, not dustyand the adherence of the coatings to the paper base was also very good.

A suitable paper base was coated with a transfer coat as set forth inExample 17 and calendered by conventional calendering techniques. Nodifficulties were encountered during the calendering of the transfercoating and after the transfer coating was calendered, it was subjectedto similar tests as set forth above. No reduction in the transferabilityof the transfer coat to the receptor coat was observed nor was anydegradation of the quality of the image observed over the non-calenderedsheets. In fact, the transfer of the image was improved when applied tothe receptor coatings probably due to the reduction in the caliper ofthe sheets and the smoothness of the transfer coating. The specificityof the transfer coating to the receptor coating when compared withordinary papers in common use was even more pronounced with thecalendered sheet than with the uncalendered sheet. In other words, thetransfer of the image to the receptor coatings of this invention using acalendered transfer coating was not degraded with respect to transfer ofthe coatings or quality of the image while it became significantly moredifficult to transfer an image from the calendered transfer coatings toordinary paper. The calendered transfer coating was also more smooth andshiny and thus was better looking and also had a better feel and papercharacteristic in general. The calendered transfer coating was even moresmudge-proof than the uncalendered transfer coating.

A suitable paper base was coated with a planographic printing surfacecomprising insolubilized polyvinyl alcohol as known in the art on oneside and the other side coated with the transfer coating formulation ofExample 17. The dried coatings were then simultaneously calendered byconventional techniques without difficulty. The planographic surface wasthen imaged in the conventional manner with a receptor sheet in contactwith the transfer coating and an excellent copy of the imaged plateobtained thereon. The plate was then placed on an off-set press andcopies produced in the conventional manner without difficulty or anyapparent degradation of the plate surface or interference with theprinting process.

All of the above transfer coatings were applied to the paper bases at acoat weight of between 3 and 6 pounds per ream and all of the abovereceptive coatings were applied to the paper base at a coat weight ofbetween about 0.5 and 2 pounds per ream. A ream, as used in thisdisclosure, is approximately 3000 square feet of paper.

I claim:

1. A manifolding system comprising a base sheet having a transfercoating on one side thereof and a base sheet having a receptor coatingon one side thereof and in which the receptor coating is in contact withthe trans fer coating, said transfer coating comprising predominantlyfinely divided inorganic platelet-type particles bound together and tothe base sheet by between about 2 and 15% by weight adhesive based onthe weight of the platelet-type particles and in which the adhesivecontains at least about 20% by weight an adhesive having a glasstransition temperature below about 40 C. and which is of a nature toyield a lightly bonded flexible transfer coating, said receptor coatingcomprising a soft resinous plastic film-forming adhesive having a glasstransition temperature of less than about 40 C. and applied to the sheetat a sufficiently low coat weight so that it is not tacky to the normalfinger touch and does not exhibit blocking characteristics in roll form.

2. The manifolding system of claim 1 in which the receptor coating isapplied to the sheet at a coat weight of between about 0.5 and 2 poundsper 3,000 square feet.

3. The manifolding system of claim 1 in which the adhesive contains atleast one member of the group consisting of styrene-butadienecopolymers, acrylic polymers and acrylic copolymers.

4. The manifolding system of claim 2 in which the transfer coatingpigment is clay.

5. The manifolding system of claim 3 in which a coloring material ispresent in the transfer coating.

6. A receptive coated paper for receiving an image transferred to saidcoating from a transfer coating containing predominantly platelet-typeinorganic pigments by means of writing pressure comprising a base paperhaving a coating adhered to one side thereof at a coat weight of betweenabout 0.5 and 2 pounds per 3,000

1 13 square feet of paper depending upon the smoothness and porosity ofthe base paper, said coating comprising a soft resinous plasticfilm-forming adhesive having a glass transition temperature below about40 C. which would normally be tacky to the touch and have blockingcharacteristics in a paper roll if applied to the paper at a coat weightabove about 2 pounds per 3,000 square feet but when applied to the paperbetween about 0.5 and 2 pounds per 3,000 square feet is not tacky to thenormal finger touch and has a strong aflinity to said transfer coatingcontaining predominantly platelet-type pigments.

7. The receptive coated paper of claim 6 in which the adhesive containsat least one member of the group consisting of styrene-butadienecopolymers, acrylic polymers and acrylic copolymers.

8. The receptive coated paper of claim 6 in which the coating containsbetween about and 125% by weight of an inorganic pigment based on theweight of the resin.

9. A copy paper having a transfer coating adhered to one side thereofand which is capable of being transferred from the surface of the paperto a receiving surface by application of writing pressure to theopposite side opposite the adhered transfer coating, said transfercoating comprising predominantly finely divided inorganic platelet-typeparticles bound together and to the base paper by between about 2 and byweight adhesive based on the weight of the platelet-type particles andin which at least about by weight of the adhesive has a glass transitiontemperature below about 40C. to produce a lightly bonded flexibletransfer coating and in which the transfer coating is calendered.

10. The method of manufacturing copy paper having a transfer coatingadhered to one side thereof which is capable of being transferred fromthe surface of the paper to a receiving surface by application ofwriting pressure to the side opposite the adhered transfer coating whichcomprises applying to the base paper sheet a coating compositioncomprising finely divided inorganic particles predominantly of theplatelet-type and between about 2 and 15% by weight adhesive based onthe weight of the platelet-type particles and in which at least 20% byweight of the adhesive has a glass transition temperature below about40C., drying coating to produce a lightly bonded transfer coating, andcalendering the transfer coating.

1 1. The method of manufacturing a duplicating master comprising a basehaving a transfer coating on one side thereof which comprises applyingto one side of the base a duplicating master coating, applying to theother side of the base a transfer coating comprising finely dividedinorganic particles predominantly of the platelet-type of between about2 and 15% by weight adhesive based on the weight of the platelet-typeparticles and in which at least about 20% by weight of the adhesive hasa glass transition temperature below about 40C., drying the coatings andsimultaneously calendering the duplicating master coating and thetransfer coating.

12. The method of claim 11 in which the duplicating master coating is aplanographic coating.

13. A duplicating master having a duplicating master coating adhered toone side thereof and a transfer coating adhered to the other sidethereof, said transfer coating comprising finely divided inorganicparticles predominantly of the platelet-type and between about 2 and 15by weight adhesive based on the weight of the platelet-type particlesand in which at least about 20% by weight of the adhesive has a glasstransition temperature below about 40C. and having both the duplicatingmaster coating and the transfer coating calendered.

14. The duplicating master of claim 13 in which the duplicating mastercoating is a planographic printing plate coating.

15. A copy paper having a transfer coating adhered to one side thereofand which is capable of being transferred from the surface of the paperto a receiving surface by application of writing pressure to theopposite side opposite the adhered transfer coating, said transfercoating comprising finely divided inorganic particles predominantly ofthe platelet-type bound together and to the base paper by between about2 and 15% by weight adhesive based on the weight of the platelet-typeparticles and in which at least about 20% by weight of the adhesive hasa glass transition temperature below about 40C. to produce a lightlybonded, flexible transfer coating.

References Cited UNITED STATES PATENTS 627,229 6/1899 Foster 117--3-6.31,845,568 2/1932 Strawn 117-36.3 2,970,931 2/ 196 1 Gumbinner 117-36.13,169,880 2/1965 Strauss 117-36.3 3,186,861 6/1965 Smith 11736.1

MURRAY KATZ, Primary Examiner.

1. A MANIFOLDING SYSTEM COMPRISING A BASE SHEET HAVING A TRANSFERCOATING ON ONE SIDE THEREOF AND A BASE SHEET HAVING A RECEPTOR COATINGON ONE SIDE THEREOF AND IN WHICH THE RECEPTOR COATING IS IN CONTACT WITHTHE TRANSFER COATING, SAID TRANSFER COATING COMPRISING PREDOMINANTLYFINELY DIVIDED INORGANIC PLATE-TYPE PARTICLES BOUND TOGETHER AND TO THEBASE SHEET BY BETWEEN ABOUT 2 AND 15% BY WEIGHT ADHESIVE BASED ONTHEWEIGHT OF THE PLATELET-TYPE PARTICLES AND IN WHICH THE ADHESIVECONTAINS AT LEAST ABOUT 20% BY WEIGHT AN ADHESIVE HAVING A GLASSTRANSITION TEMPERATURE BELOW ABOUT 40*C. AND WHICH IS OF A NATURE TOYIELD A LIGHTLY BONDED FLEXIBLE TRANSFER COATING, SAID RECEPTOR COATINGCOMPRISING A SOFT RESINOUS PLASTIC FILM-FORMING ADHESIVE HAVING A GLASSTRANSITION TEMPERATURE OF LESS THAN ABOUT 40*C. AND APPLIED TO THE SHEETAT A SUFFICIENTLY LOW COAT WEIGHT SO THAT IT IS NOT TACKY TO THE NORMALFINGER TOUCH AND DOES NOT EXHIBIT BLOCKING CHARACTERISTICS IN ROLL FORM.